Backflow testing device

ABSTRACT

A handheld-sized, single-hand-holdable, single-hand-operable battery-powered digital backflow prevention assembly testing gage capable of measuring a differential pressure between high and low side fluid sources, providing a capture value function for easily recording pressure values while continuing display of live pressure measurements, and providing a rate of change graph display for immediate visual indication of changes in the differential pressure being sensed. The design utilizes a true differential pressure sensor for more accurate measurements, provides for use as a 5-valve, 3-valve, or 2-valve tester conforming to standard industry field testing procedures, and permits wireless transmission of measurement and related data as well as remote wireless calibration of the testing device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of U.S. patent application Ser. No. 16/422,772,filed on May 24, 2019, and entitled “BACKFLOW TESTING DEVICE.” Theentire contents of the above-listed application is hereby incorporatedby reference for all purposes.

BACKGROUND OF THE INVENTION

The technical field of invention relates to test equipment for measuringpressures associated with backflow prevention assemblies. Moreparticularly, the present invention pertains to a hand-held,single-hand-sized backflow testing device for measuring fluid pressureand fluid pressure differentials, and for testing fluid control devicessuch as vacuum breakers, check valves, and pressure relief valves.

Several different designs for backflow testing devices have beendisclosed in various publications and products. The different designsprovide various features and capabilities. For example, the Manual ofCross-Connection Control, published in its first edition in 1960 and now(most recently) in its tenth edition in 2009 by the Foundation forCross-Connection Control and Hydraulic Research, a division of theUniversity of Southern California (“Manual of Cross-Connection Control”or “MCCC” or “USC FCCCHR”) includes comprehensive field test proceduresfor 2-valve, 3-valve, and 5-valve configuration field test kits. Asdisclosed in the USC FCCCHR, each test kit comprises an analog dialdifferential pressure gage for measuring a pressure differential betweena high side fluid line and a low side fluid line. The 2-valveconfiguration includes two valves and four connections—a high side valveand port, a high side bleed port, a low side valve and port, and a lowside bleed port. The 3-valve configuration includes three valves andthree connections—a high side valve and port, a bypass (sometimesreferred to as “Vent”) valve and port, a low side valve and port. Andthe 5-valve configuration includes five valves and five connections—ahigh side bleed valve and port, a high side valve and port, a bypass(sometimes referred to as a “Vent) valve and port, a low side valve andport, and a low side bleed valve and port. Each of these analog dialtype gage test kits are very basic, non-electronic devices, offeringonly continuous live analog pressure readings.

U.S. Pat. No. 5,257,208 by Brown et al. (“Brown”) discloses acomputerized portable testing device that displays and prints pressurevalues (of a high side and a low side) and their (calculated) difference(i.e. a calculated pressure differential). The device in Brown comprisestwo valves and four connections—a high side bleed valve and port, a highside port, a low side bleed valve and port, and a low side port. A“Transducer A” is used to measure a high side pressure, and a“Transducer B” is used to measure a low side pressure. And an “A-B”calculated pressure difference is presented as a differential pressureor apparent pressure drop. The device disclosed in Brown also includes a“display hold” button that causes the pressure readings on the displayto remain unchanged while the button is depressed.

The Watts TK-DL digital print-out test kit for backflow preventerassemblies comprises the form, function, and features of the devicedisclosed and described in Brown. Also referenced in Brown is a backflowtesting device from Duke Products. Similar to Brown and the Watts TK-DLdevices, the Duke Model EZ 900 comprises two valves and fourconnections—an “A” or high side inlet, a high side bleed (or vent) valveand port (vent), a “B” or low side inlet, and a low side bleed (or vent)valve and port (vent). A first transducer measures pressure in fluidline “A”, and a second transducer measures pressure in fluid line “B”. Asubtractive calculated “A-B” differential pressure is displayed, alongwith values for the pressure in line “A” and the pressure in line“B”.The Duke Model EZ 900 includes a “Hold” button that, like the WattsTK-DL, causes the pressure readings on the display to remain unchanged.

Another device is the Watts TK-99D digital backflow preventer test kit,which comprises three valves and three connections—an “A” side port, an“A” side bleed valve, a bypass control valve and port, a “B” side bleedvalve, and a “B” side port. As in the Watts TK-DL, Brown, and Duke ModelEZ 900, the Watts TK-99D device comprises two separate (“A” and “B”)pressure sensors and provides the subtractive difference “A-B” asdifferential pressure. Other than separate single function on and offbuttons, the Watts TK-99D includes no other button controllablefunctions or features.

US patent application publication no. US 2015/0051848 by Jurkowitz(“Jurkowitz”), published Feb. 19, 2015, with applicant identified asNicholson Labs, Inc., discloses an electronic tester comprising fivevalves and four connections—a high side port, a high side control valve,a bypass control valve and port, a low side control valve, a low sideport, a low side bleed valve, a high side bleed valve, and a commonoutlet (port) associated with the low side bleed valve and the high sidebleed valve. As in the Watts TK-DL, Brown, Duke Model EZ 900, and WattsTK-99D, the device in Jurkowitz utilizes two separate transducers, oneto sense pressure on the high side fluid line, and the other to sensepressure on the low side fluid line. A differential pressure is thencalculated as the difference between the values returned by each of thetwo transducers. Jurkowitz discloses that the device, comprising fivevalves and four connections, may be configured as either a 3-valvetester or a 5-valve tester, conforming with industry specified testinginstructions (such as, for example, those instructions set out in theUSC FCCCHR).

Each of the existing backflow testing device designs has disadvantagesin terms of cost, complexity of design, ease of use, feature content,method of recommended and actual use, form factor and ergonomics of thedevice, design aesthetics, and/or other factors. What is needed aredesigns for a hand-held, single-hand-sized backflow testing device formeasuring fluid pressure and fluid pressure differentials, and fortesting water control devices such as vacuum breakers, check valves, andpressure relief valves, that address one or more disadvantage ofexisting designs.

The foregoing and other objectives, features, and advantages of theinvention will be more readily understood upon consideration of thefollowing detailed description of the invention taken in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL DRAWINGS

For a more complete understanding of the present invention, the drawingsherein illustrate examples of the invention. The drawings, however, donot limit the scope of the invention. Similar references in the drawingsindicate similar elements.

FIG. 1 is a front/left/bottom perspective view of a hand-held backflowtesting device, according to preferred embodiments.

FIG. 2 is a back or rear elevation view of the backflow testing deviceshown in FIG. 1, according to preferred embodiments.

FIG. 3 is a functional block diagram of a backflow device according topreferred embodiments.

FIG. 4 is an illustration of various components of a backflow device, asviewed from the front and with a housing enclosure hidden, according topreferred embodiments.

FIG. 5 is an illustration of various components of a backflow device, asviewed from the back and with a housing enclosure hidden, according topreferred embodiments.

FIG. 6 depicts exemplary display graphics for a backflow testing device,according to preferred embodiments.

FIG. 7 is a flow diagram for a capture button/capture value(s) process,according to preferred embodiments.

FIG. 8 is a flow diagram for a powering off process, according topreferred embodiments.

FIG. 9 is a flow diagram for a rate of change graph (ROCG) process,according to preferred embodiments.

FIG. 10 illustrates an exemplary rate of change graph display showing astable pressure differential, according to preferred embodiments.

FIG. 11 illustrates an exemplary rate of change graph display showing anincreasing pressure differential, according to preferred embodiments.

FIG. 12 illustrates an exemplary rate of change graph display showing adecreasing pressure differential, according to preferred embodiments.

FIG. 13 is hydraulic circuitry for a 5-valve configuration of a backflowtesting device, according to preferred embodiments.

FIG. 14 is a front/left/bottom perspective view of a 3-valveconfiguration of a backflow testing device, according to preferredembodiments.

FIG. 15 is hydraulic circuitry for a 3-valve configuration of a backflowtesting device, according to preferred embodiments.

FIG. 16 is a front/left/bottom perspective view of a 2-valveconfiguration of a backflow testing device, according to preferredembodiments.

FIG. 17 is hydraulic circuitry for a 2-valve configuration of a backflowtesting device, according to preferred embodiments.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In the following detailed description, numerous specific details are setforth in order to provide a thorough understanding of the preferredembodiments. However, those skilled in the art will understand that thepresent invention may be practiced without these specific details, thatthe present invention is not limited to the depicted embodiments, andthat the present invention may be practiced in a variety of alternateembodiments. In other instances, well known methods, procedures,components, and systems have not been described in detail.

Preferred embodiments comprise a handheld-sized, single-hand-holdable,single-hand-operable battery-powered backflow prevention assembliestesting device (or gage) that is fluidly connectable to a high sidefluid source and to a low side fluid source, and that is capable ofmeasuring the differential pressure between the high and low side fluidsources using a single differential pressure sensor fluidly connected toeach of the high and low side fluid sources via respective high and lowside fluid lines. A preferred ergonomic form-factor for such a backflowtesting device is illustrated in FIGS. 1 and 2, with FIG. 1 showing afront/left/bottom perspective view of such device 100, and FIG. 2showing a back side of such device 100. Preferred embodiments comprise acapture button 105 and captured value functionality as described withrespect to FIGS. 1, 6, and 7. Preferred embodiments comprise rate ofchange graph (ROCG) display and functionality as described with respectto FIGS. 6 and 9-12. Preferred embodiments comprise a device 100 capableof being configured as any one of a 2-valve tester, a 3-valve tester ora 5-valve tester, conforming with industry specified testinginstructions (such as, for example, those instructions set out in theUSC FCCCHR), as described with respect to FIGS. 1, 4, 5, and 13.Further, preferred embodiments comprise simple variants of the full5-valve and 5-connection device 100, which corresponds to the hydrauliccircuitry in FIG. 13, including a 3-valve/3-connection device 1400described in FIGS. 14-15 and a 2-valve/4-connection device 1600described in FIGS. 16-17, each of the devices 100, 1400, and 1600conforming with industry specified testing instructions such as thoseset out in the USC FCCCHR manuals, the most current at the time of thispublication being Manual 10.

Although the preferred embodiments may be described in the context of5-valve, 3-valve, and 2-valve configurations of an electronic digitalbackflow testing device each having a combination of the novelinnovations described herein—for example, use of a single (true)differential pressure sensor (as opposed to existing designs that usemultiple transducers and computing a (subtractive) apparent differentialpressure; use of an ergonomic form-factor enabling single-hand operationfor measured value capturing; incorporation of a capture value buttonand display of both continued live readings and captured values;incorporation of a rate of change graph (ROCG) providing immediatevisual queues as to the rate of change in sensed differential pressure;flexibility in a 5-valve/5-connection version of a backflow testingdevice allowing the device to be used in a 5-valve configuration, or a3-valve configuration, or a 2-valve configuration (in conformance withindustry field testing standards); and a simplicity of design (i.e.reduced complexity) enabling the backflow device to be manufactured andsold in 5-valve/5-connection, 3-valve/3-connection, and2-valve/4-connection variants—each of the described innovations, amongothers described herein, are separable and may be applied in differentcombinations and to devices adapted for other, non-backflow testingapplications.

A front/left/bottom perspective view of a hand-held backflow testingdevice 100 is illustrated in FIG. 1, according to preferred embodiments.As shown, the device 100 preferably comprises a hand-held sized housinghaving a top 160, bottom 166, left side 164, right side 162, front 170and back 172. The present inventors discovered that the layout ofconnections, controls, and interfaces, as illustrated, provide improvedergonomics and an easier to use form factor. The housing is preferablysized to permit single hand operation of at least the capture valuebutton 105 and preferably also the back button 106, and thepower/backlight button 107. A display 168 is preferably centrallylocated, as shown, on the front 170 of the device 100. The housing ofdevice 100 is preferably shaped as illustrated, with an upper portionprotruding from the left side 164, having low side and high side bleedports 101, 103 on an upper left side face of the housing andcorresponding low side bleed port and high side bleed port knobs 102,104 on an upper left front face portion. The housing is preferablyshaped as shown so that a user may hold the device 100 in a left handalong its left side 164 just below the high and low side bleed ports103, 101, with the user's fingers wrapped around to engage with the back172 and structures and features thereon, and easily depress either thecapture value button 105 or back button 106 on the front 170 of thedevice using the left thumb. The user may then adjust any one of theknobs 102, 104, 109, 111, 113 using the other (free) hand, with highside port 110, bypass port 112, and low side port 114 connectionsextending from the bottom 166 of the device 100.

Each of the knobs (for opening and closing a fluid flow controllingvalve) is preferably located directly in view and proximate to theport/connection that the knob (and valve) affects. As illustrated inFIG. 1, all of the knobs 102, 104, 109, 111, and 113 are preferably onthe front 170 of the device, and each of the respectiveports/connections 101, 103, 110, 112, and 114, respectively, arepreferably immediately in view and proximate to the knob that controlsfluid flow for the particular port/connection. As shown, low side bleedport knob 102 is proximate to low side port 101; high side bleed portknob 104 is proximate to high side port 103; high side pressure portknob 109 is proximate to high side pressure port 110; bypass controlknob 111 is proximate to bypass port 112; and low side pressure portknob 113 is proximate to low pressure port 114.

The present inventors discovered that the form-factor depicted in FIG. 1(and FIGS. 2, 14, and 16) is more effective and practical for theuser/technician than existing electronic or digital devices, or moretraditional test kit designs comprising a central (typically analog)gage and (exposed/non-housing enclosed) valving manifolds surroundingthe gage. In operation, all or at least one of the connections 101, 103,110, 112, and 114 may be connected to tubing or hoses. For example,tubing may be connected to bleed ports 103, 101, for redirecting fluiddirected through those ports, and hoses are preferably connected to thehigh side, bypass, and low side ports 110, 112, 114, respectively.Tubing or hoses connected to the ports/connections 101, 103, 110, 112,and 114 extend away from the sides of the device 100 either vertically(such as to the left from ports 101 and 103) or downward (such as fromports 110, 112, and 114), as opposed to upward and/or rearward.Consequently, all fluid paths into and out of the device 100 (as well asany knobs controlling valves that affect those fluid paths) areimmediately visible by a technician when looking at the backflow testingdevice 100 from the front 170.

Conventional test kits use hoses that are color coded, with red-coloredhose used for fluid connection to a high side fluid line to be tested, ayellow-colored hose to be fluidly connected with a bypass fluid testconnection, and a blue-colored hose to be fluidly connected to a lowside fluid line to be tested. The knobs 102, 104, 109, 111, and 113preferably incorporate color to match their corresponding operation.High side bleed port knob 104 and high side port knob 109 mayincorporate the color red to indicate their connection to the high sidefluid line under test. The bypass port knob 111 may incorporate thecolor yellow to match a yellow colored hose connected to the bypass port112. And the low side bleed port knob 102 and low side port knob 113 mayincorporate the color blue to indicate their connection the low sidefluid line under test.

The present inventors discovered that orienting the fluid connectionsand corresponding valves in a consistent relation to the technician andin a consistent fashion as compared to industry specified testinginstructions (such as, for example, those instructions set out in theUSC FCCCHR manual), improved ease of use of the device. Fluid (or water)control devices such as vacuum breakers, check valves, and pressurerelief valves, are typically illustrated in hydraulic schematics ordiagrams with the direction of fluid flow going from left to right, fromregions of high pressure to (in typical operation) regions of (expected)lower pressure, or from a supply source to an intended discharge ordestination. Preferably, as shown in FIG. 1, the high side connectionsand ports are positioned closest to the technician's left hand whilegripping the device 100 in a left hand along the side 164 of the device,and the low side connections and ports are farther away (either upwardor to the right) from the technician's left hand while gripping thedevice in a left hand along the side 164. For example, the high sideport/connection 110 is preferably positioned on the left portion of thebottom 166, and the low side port/connection 114 is preferablypositioned on the right portion of the bottom 166; similarly, the highside bleed port 103 is positioned closer to the left grip location, andthe low side bleed port 101 is positioned farther from the left griplocation.

FIG. 2 is a back or rear elevation view 200 of the backflow testingdevice 100 shown in FIG. 1, according to preferred embodiments. Therearmost surface 172 preferably comprises a narrow ridge extending in atop 160 to bottom 166 direction, and positioned toward a left side 164of the device 100. A similarly formed second ridge is preferablypositioned toward a right side 162 of the device 100, as shown in FIG.2. The present inventors discovered the ridges provide improved gripwhen holding the device. The valley formed between the two ridges formsa surface upon which is formed a condensate moisture vent 217, inpreferred embodiments. The vent 217 allows condensate moisture to escapefrom within the device housing and preferably includes porous materialthat allows moisture to escape from within the device and preventsexternal water or other fluids from entering the housing. A hook with(nylon) strap 215 is preferably included, stowable within a grooveformed in the (valley/back) surface and retained in a stowed positionusing a retainer clip 216. A battery compartment is preferably formedinto this (valley/back) (shown in FIG. 2 with the battery coverremoved). A battery cover gasket 221 is preferably used to keep water orother fluid out of the battery compartment when the battery cover issecured in place via battery compartment fasteners 219. A battery covercutout or lip 220, as shown, is preferably included to simplify removalof the battery cover.

FIG. 3 is a functional block diagram 300 of a backflow preventionassembly testing device, such as device 100, according to preferredembodiments. Preferably, a single differential pressure sensor 304 isused for sensing a true differential fluid pressure between a high side306 and a low side 308. The differential pressure sensor 304 preferablyreceives high side water and water pressure 306 and low side water andwater pressure 308 and generates an analog voltage (or current) that isproportionate to or that varies as a function of the differentialpressure between high and low sides. An analog to digital converter(ADC) 302, which may be integral to a differential pressure sensormodule, converts the sensor voltage (or current) to a digital numberrepresenting a magnitude of the sensed pressure differential. And thedigital value (number) is then received by a central processing unit(CPU) (or microprocessor, or microcontroller/MCU/μ-controller) 312.

Known existing electronic/digital backflow testing devices utilize atleast two pressure sensors—one to sense a high side pressure, and theother to sense a low side pressure—and calculate a differential pressureas the low side pressure reading subtracted from the high side pressurereading. In less preferred embodiments, the differential pressure sensor304 may comprise at least two pressure sensors—one to sense a high sidepressure and the other to sense a low side pressure—with an apparentdifferential pressure mathematically calculated as the differencebetween sensor measurements. However, the present inventor discoveredthat utilizing a single pressure sensor improves accuracy andreliability, at least in part due to eliminating the additional sourcesof error caused by using two sensors instead of one. The presentinventor realized that a conventional pressure sensor senses a pressurein relation to either a vacuum (for pressure measurements in, forexample, PSIA or pounds per square inch absolute) or atmosphericpressure (for pressure measurements in, for example, PSIG or pounds persquare inch gage), and that calibrations are critical for obtainingreliable and repeatable pressure readings. The present inventordiscovered that by using a differential pressure sensor (whereby asingle sensor is measuring a physical pressure difference between twosides of the sensor assembly) improves accuracy by reducing thecompounding of errors inherent in multiple sensor devices.

In preferred embodiments, Power for the CPU 312 is preferably providedby power supply or batteries 314. Physical switch or button inputs 310to the CPU 312 preferably comprise a capture button 105, back button106, and a power/backlight button 107. The CPU 312 preferably controls adisplay/display circuitry 320 and a buzzer/speaker 318 for audioalerts/indications. A wireless communications module 316 is preferablyprovided, comprising circuitry for wirelessly transmitting and receivingdata, commands, programming instructions, or other information. Inpreferred embodiments, a smartphone or mobile device application may bewirelessly coupled with the wireless communications module 316, with thewireless communications module 316 used for wirelessly transmittingcaptured and live pressure readings, captured value identifierinformation saved in memory, gage calibration date information saved inmemory, and/or other information saved in memory such as gage serialnumber, firmware version, battery life, and units settings. Gagecalibration is preferably adjusted via wireless transmission and use ofan app downloaded to a smartphone or mobile device, which the presentinventors discovered makes the calibration process easier than withcurrently available mechanical gages.

The backflow testing device 100, as shown in FIG. 1, comprises a5-valve/5-connection device, and FIGS. 4 and 5, illustrate the device100 with its housing hidden/removed. FIG. 4 is an illustration 400 ofvarious components of the backflow device 100, as viewed from the front(with its housing enclosure hidden), and FIG. 5 is an illustration 500of various components of the backflow device, as viewed from the back(again, with its housing enclosure hidden), according to preferredembodiments. For greater understanding of FIGS. 4 and 5, the hydrauliccircuitry in FIG. 13 is provided, which corresponds to the hydrauliccircuitry for the 5-valve/5-connection configuration of device 100,according to preferred embodiments.

Hoses (not shown) may be connected to each of the threaded fittings 110,112, and 114, which are shown in FIGS. 4 and 5 attached to a pressureports manifold 423. The threaded fittings 110, 112, and 114 comprisehigh side, bypass, and low side connections/ports, respectively. Thepressure ports manifold 423 is preferably primarily used to exchangefluid between the high and low side of the gage (that is, between highside port 110 and low side port 114), and to and from the bypass port112—which are capabilities useful for various field testing procedures,for example, for testing of Reduced Pressure Backflow Assemblies(RPBAs). The pressure ports manifold 423 comprises an uninterruptedfluid path between the high side connection/port (fitting) 110 and ahigh side inbound pipe 531; an uninterrupted fluid path between the lowside connection/port (fitting) 114 and a low side inbound pipe 530; afluid path between high side port 110 and low side port 114 having avalve controlled by the high pressure port knob 109, a valve controlledby the low pressure port knob 113, and a bypass port 112 with a bypassport valve controlled by the bypass port knob 111 positionedtherebetween, consistent with the hydraulics circuitry shown in FIG. 13.

As shown in FIGS. 4 and 5, the high side sensor block (or manifold) 427and the low side sensor block (or manifold) 428 preferably hold thedifferential pressure sensor 532 in place, with the high side sensorblock 427 comprising an uninterrupted fluid path from the high sideinbound pipe 531 to a high side outbound pipe 425 and an uninterruptedfluid path to a high side of the sensor 532, and the low side sensorblock 428 comprising an uninterrupted fluid path from the low sideinbound pipe 530 to a low side outbound pipe 424 and an uninterruptedfluid path to a low side of the sensor 532. The high side sensor block427 preferably exposes the high side of the differential pressure sensor532 to fluid and fluid pressure from the high side port 110, and the lowside sensor block 428 preferably exposes the low side of thedifferential pressure sensor 532 to fluid and fluid pressure from thelow side port 114.

The bleed ports manifold 422 shown in FIGS. 4 and 5 preferably directair and water (fluid) out of the gage (out of device 100) and intoeither the environment directly or through bleed port hoses (not shown)that may be connected to either or both of the high side bleedport/connection 103 and low side bleed port/connection 101. The bleedports manifold 422 preferably comprises a fluid path from the high sideoutbound pipe 425 to the high side bleed port/connection 103, a valvecontrolled by high side bleed port knob 104 for controlling fluid flowthrough the high side bleed port/connection, a fluid path from the lowside outbound pipe 425 to the low side bleed port/connection 101, and avalve controlled by low side bleed port knob 102 for controlling fluidflow through the low side bleed port/connection, consistent with thehydraulics circuitry shown in FIG. 13. A primary use of the bleed portsmanifold, in preferred embodiments, is to ensure there is no air in thedevice fluid lines while taking pressure measurements.

In preferred embodiments, the differential pressure sensor 532 convertsthe high side fluid pressure and the low side fluid pressure into apressure differential, which is then communicated to a printed circuitboard (PCB) 429 via an electrical signal. The PCB 429 is preferablypositioned between the display 168 and batteries 533 used for providingelectrical power to the device 100. The PCB 429 preferably includes allthe electrical components necessary to receive sensor anduser/technician inputs from buttons 105, 106, and 107, process thoseinputs in the CPU and generate outputs useful to the user/technician viaa piezoelectric buzzer 426 and LCD (display) 168. The buzzer 426, inpreferred embodiments, provides audio feedback to the user/technicianwhen certain actions or events have been performed and understood by thelogic of the device 100 firmware. For example, a beep may be sounded forthe capturing of a measurement via the capture button 105.

The present inventors discovered novel and effective placement andfeatures for the display 168 in the backflow testing device 100. FIG. 1illustrates a preferable proportion and placement of the display 168,preferably a large display covering a large portion of the front 170 ofthe device and centrally positioned below the capture button 105 andback button 106, and positioned so as not to be covered or hidden whenthe device 100 is held in the technician's hand. The present inventorsfurther discovered placement of the display 168 on the front 170 ofdevice 100 so that the sensor 532 is positioned (behind the display 168and) in line with the rate of change graph (ROCG) 602 (described ingreater detail below with respect to FIG. 6) provides theuser/technician with an indication of the position of the sensor withinthe device 100 and establishes an elevation of the field test kit(backflow testing device), helping the user/technician position the gageappropriately during testing. The USC FCCCHR discloses, for certaintesting procedures, keeping the field test kit and unused hoses at anappropriate elevation with respect to a visible downstream referencepoint such as a test cock or water level in a sight tube, if used. Thepresent inventors discovered that placement of the rate of change graph602 so that the horizontal graphical display comprising the rate ofchange graph 602 provides a (horizontal line) visual indication of theelevation of the testing gage allows for easier alignment of theelevation of the testing gage with a visible downstream reference point.

The present inventors discovered novel and especially useful graphicsand features utilizing the display 168. FIG. 6 depicts exemplary displaygraphics 600 for a backflow testing device, according to preferredembodiments. The display graphics 600 preferably comprise a main display604 comprising large (easy to view from a distance) numeric presentationof a current, live reading of the differential pressure, with a unitsindication 620 whether the reading is being displayed in PSID (poundsper square inch differential) or KPaD (kilopascals differential). Inpreferred embodiments, the units indication 620 may be toggled betweenreadings in PSID and KPaD by holding down the capture button 105 whilepowering on the unit via power/backlight button 106, and thepower/backlight button 106 toggles the display backlight on and off bybriefly pressing and releasing the power/backlight button 106.

The present inventors discovered improvements in the informationprovided to the technician in providing that, in most preferredembodiments, the main display 604 comprise a continuous live reading ofthe pressure differential being sensed between the high side fluid lineand the low side fluid line. That is, the main display 604 provides acurrent, live reading (measurement) display of the differential pressurefree from a hold button or hold function such as those used onconventional/existing digital electronic backflow testing devices. Thepresent inventors discovered and invented a capture value functionpreferably comprising a capture button 105 that, instead of freezing theactive/current/live readings display (such as by using a hold button),is used to capture (and separately display) a differential pressurereading value. The present inventors developed a captured value functionwhereby a captured value 606 is displayed below the main (live reading)display 604, with the live reading display 604 being uninterrupted,continuing to display a live pressure differential reading. Preferably,more than one value may be captured and separately displayed. As shownin FIG. 6, an active position cursor 608 is preferably used to showwhich position the next captured value will be saved to, and a capturedvalue identifier (ID) 622 provides a label for the captured value (or acapture position for the captured value). In preferred embodiments, andas shown in the exemplary graphics display 600, up to six capturedvalues may be displayed, each with a captured value ID 622, while themain display 604 continues to display the current, real time livereading from the differential pressure sensor. In preferred embodiments,a back button 106 (as shown in FIG. 1) is used to clear previouslycaptured values. For example, the technician may press the back button106 once to delete the previous captured value and hold the back button106 down for 1.5 seconds to clear all captured values. In otherembodiments, the back button 106 may be configured to move the activeposition cursor 608 to a particular captured value, to be overwrittenusing the capture value button 105 or deleted by pressing the backbutton 106. In still other embodiments, other combinations of pressingand holding the back button 106 may be used to manage the capturedvalues displayed on display 168.

The present inventors discovered and invented a rate of change graph(ROCG) 602 preferably displayed immediately above the current, livereading of the main display 604, whereby the rate of change graphprovides the technician with an immediate visual indication of howquickly and in which direction (up or down) the differential pressuremeasurement is changing. As illustrated and described below with respectto FIGS. 10, 11, and 12, when a reading is stable (no change indifferential pressure) the ROCG bar 602 will have a single dot (filledin) in the middle; when differential pressure is increasing, the ROCG602 will comprise a number of filled in arrows (or chevrons) to theright proportionate to the rate of increase; and when differentialpressure is decreasing, the ROCG 602 will comprise a number of filled inarrows to the left proportionate to the rate of decrease. The presentinventors discovered the rate of change graph (ROCG) is especiallyuseful for helping the technician determine the pressure at the momentthe relief valve on a reduced pressure backflow assembly (RPBA) opens byallowing them to more accurately determine the pressure bleed rate, isuseful to help the technician get a feel for stable and unstable waterpressures for determining when a test will yield good results and whenthe pressure is too volatile to perform a good test and is very helpfulin troubleshooting.

Moreover, as previously mentioned, in preferred embodiments the ROCG bar602 is positioned in line with the pressure sensor 532 to help theuser/technician orient the backflow testing device 100 in relation tothe backflow prevention assembly being tested. In preferred embodiments,the middle dot between right and left pointing arrows comprising theROCG bar 602 is positioned within the display 168 so that the sensor 532is physically located within the interior volume of device 100 to besubstantially directly behind the middle dot 1021 (shown in FIGS. 10,11, and 12) of the rate of change graph displayed on display 168.

Several indicators are preferably positioned along the top row of thedisplay graphics 600. As shown in FIG. 6, an auto power off (APO)indicator 610 is preferably set (as a device default) to automaticallypower off the device after 30 minutes of inactivity in order to conservebattery life. The APO feature may be disabled (turning the APO indicator610 off) by holding down the back button 106 while powering on thedevice. A calibration (CAL) indicator 612 is preferably included to showwhen the unit is currently in calibration mode. A download indicator 614is preferably included to show that a firmware update is beingdownloaded into the device. A wireless connection indicator 616 ispreferably included to show that the device is currently connected to amobile device, such as when the backflow device is connected to anassociated app (downloaded to and operating on the wirelessly connectedmobile device) for downloading new firmware, calibrating the backflowtesting device, receiving measurement and data from the backflow testingdevice, or any time the device 100 is transmitting or receivinginformation with a mobile device. And a battery life indicator 618 ispreferably included to show approximate battery life remaining. Inpreferred embodiments, when battery life reaches zero bars, the emptybattery icon will begin to blink at a rate of 1 Hz; and when batterylife is critically low, a warning tone is played before the unit shutsdown.

FIG. 7 is a flow diagram for a capture button/capture value(s) process700, according to preferred embodiments. As shown, when atechnician/user presses 702 the capture button, a determination 704 ismade whether a current capture counter is less than a maximum count(such as, for example, six). If not, the process ends 718 since allavailable captured value locations are used (until cleared). If thecurrent capture counter is less than the maximum, the current pressurevalue is stored 706, the current capture counter is incremented 708, thecurrent capture location indicator is updated on the display 710, thecaptured value is written to the display in the current capture location712, the buzzer is activated to provide audio feedback to theuser/technician 714, the capture counter value is incremented 716, andthen the process ends 718.

FIG. 8 is a flow diagram for a powering off process 800, according topreferred embodiments. As shown, when a user/technician presses 802 thepower button to turn the unit off, the capture counter, captured values,and current capture location counter are written to non-volatile memory804 before the unit shuts down. The information saved in memory is thenavailable upon power up.

FIG. 9 is a flow diagram for a rate of change graph (ROCG) process 900,according to preferred embodiments. As shown, pressure is read into theMCU and stored as a temporary variable 902. The pressure reading is thencompared with the previous reading 904, and a rate of change iscalculated 906. A lookup table and the calculated rate of change areused to determine a graph display 908, and the display is updated withan appropriate number of bars (filled in arrows) to indicate rate ofchange. And the process repeats, whereby pressure is (again) read intothe MCU and stored as a temporary variable 902.

FIGS. 10, 11, and 12 are exemplary rate of change graph (ROCG) 602displays for stable, increasing, and decreasing pressure differential,respectively. FIG. 10 illustrates an exemplary rate of change graphdisplay 1000 showing a stable pressure differential, according topreferred embodiments. As shown, when the pressure differential isstable (not changing), the middle dot (or diamond) 1021 is filled in andthe rest of the (ten) arrows (1001 through 1010) to the right and (ten)arrows (1011 through 1020) to the left are left unfilled. Or, when thepressure differential is relatively (more or less) stable, there may beone or two arrows filed in either direction. For example, and not shown,a rate of change graph having the middle dot 1021 and arrow 1001 filledin, with the rest of the arrows unfilled, would represent a stablepressure differential. In preferred embodiments, the first arrow (1001and 1011) on each side of the middle dot 1021 show a change in pressureof +/−0.05 PSID/second. More or less arrows may be used, and the shapesneed not be as shown (as arrows).

FIG. 11 illustrates an exemplary rate of change graph display 1100showing an increasing pressure differential, according to preferredembodiments. As shown, when the pressure is increasing, the arrows 1001,1002, 1003, and 1004 on the right side will be darkened (in addition tothe middle dot 1021). The faster the pressure differential isincreasing, the more arrows to the right of the middle dot 1021 will bedarkened (filled).

FIG. 12 illustrates an exemplary rate of change graph display 1200showing a decreasing pressure differential, according to preferredembodiments. As shown, when the pressure reading is decreasing, thearrows 1011, 1012, 1013, and 1014 on the left side will be darkened. Thefaster the pressure differential is decreasing, the more arrows to theleft of the middle dot 1021 will be filled (darkened).

Turning now to FIGS. 13-17, the present inventors discovered that simplevariants of the full 5-valve and 5-connection device 100, whichcorresponds to the hydraulic circuitry in FIG. 13, may comprise a3-valve/3-connection device 1400 described in FIGS. 14-15 and a2-valve/4-connection device 1600 described in FIGS. 16-17, such thateach of the devices 100, 1400, and 1600 conform with industry specifiedtesting instructions such as those set out in the USC FCCCHR Manuals.For simplicity of description with respect to the hydraulic circuitry inFIGS. 13, 15, and 17, references to ports/connections and fittings arecombined, and references to valves and knobs are combined. For example,FIG. 13 comprises hydraulic circuitry for the 5-valve/5-connectiondevice 100 in FIG. 1, according to preferred embodiments. The knobs 102,104, 109, 111, and 113 shown in FIG. 1 correspond to the valves theycontrol, respectively, to the valves 102, 104, 109, 111, and 113 shownin FIG. 13. The ports (or connections) 103 and 101 shown in FIG. 1 asbleed ports or bleed port tubing fittings, are shown as simplyconnections 103 and 101 in FIG. 13. And the ports (or connections) 110,112, and 114 shown in FIG. 1 as high side, bypass (or vent), and lowside ports, respectively, each comprising a threaded fitting, are shownas simply connections/ports 110, 112, and 114 in the hydraulic circuitryin FIG. 13.

The present inventors discovered that the same housing used for thedevice 100 shown in FIG. 1 may be used for a 3-valve/3-connectionconfiguration/version 1400 illustrated in FIG. 14, with correspondinghydraulic circuitry 1500 shown in FIG. 15. The same housing is used forboth the 5-valve device 100 and the 3-valve device 1400. For the 3-valvedevice 1400, closure caps 1450 and 1452 replace the threaded fittingsshown in those locations for the 5-valve device 100. Where device 100included bleed ports, the 3-valve device 1400 uses those connections asthe high side port/connection (threaded fitting) 1410 and low sideport/connection (threaded fitting) 1414. And the 3-valve device 1400comprises a high side pressure port knob 1409, a low side pressure portknob 1413, and a bypass (or vent, or bleed) port knob 1411 with bypass(or vent, or bleed) port (threaded fitting) 1412.

The present inventors further discovered that the same housing used forthe device 100 in FIG. 1 (and used for the device 1400 in FIG. 14) maybe used for a 2-valve/4-connection configuration/version 1600illustrated in FIG. 16, with corresponding hydraulic circuitry 1700shown in FIG. 17. The same housing is used for the 5-valve device 100,the 3-valve device 1400, and the 2-valve device 1600. For the 2-valvedevice 1600, a closure cap 1650 replaces the threaded fitting shown inthat (bypass) location for the 5-valve device 100 and the 3-valve device1400. Where device 100 included high side and low side bleed ports withbleed port tubing fittings, the 2-valve device includes high side 1603and low side 1601 bleed ports with threaded fittings (so that a bypasshose may be used with ports 1603 and 1601).

The present inventors developed each of the aforementioned 5-valvedevice 100, 3-valve device 1400, and 2-valve device 1600 to be able toperform all standard backflow testing procedures including those fromUSC FCCCHR, ABPA, NEWWA, AWWA, UF TREEO, and ASSE.

The terms and expressions which have been employed in the foregoingspecification are used therein as terms of description and not oflimitation, and there is no intention in the use of such terms andexpressions of excluding equivalents of the features shown and describedor portions thereof, it being recognized that the scope of the inventionis defined and limited only by the claims which follow.

What is claimed is:
 1. A digital backflow testing device comprising: afirst fluid line connectable to a first source of fluid and a firstfluid pressure therefor; a second fluid line connectable to a secondsource of fluid and a second fluid pressure therefor; a truedifferential pressure sensor in fluid communication with said first andsaid second fluid lines and configured to sense a pressure differentialbetween said first and said second fluid lines; and electrical circuitryconfigured to provide differential pressure measurements from saidpressure differential sensed by said true differential pressure sensor.2. The device of claim 1 wherein the true differential pressure sensorcomprises a single true differential pressure sensor configured to sensethe differential fluid pressure between said first and said second fluidlines and does not require electronic circuitry configured to calculatethe differential fluid pressure between said first and said second fluidlines by using more than one pressure sensor to obtain pressuremeasurements for each of the first and second fluid lines and thencalculating the differential fluid pressure as a calculated differencebetween pressure measurements of said first and said second fluid lines.3. The device of claim 1 further comprising: electrical circuitry and anelectronic display configured to display said differential pressuremeasurements.
 4. The device of claim 1, further comprising: a batterypower supply electrically interconnected with said true differentialpressure sensor and an electronic display.
 5. The device of claim 1,further comprising: electrical circuitry and an electronic displayconfigured to display real time measurements of said differentialpressure.
 6. The device of claim 1, further comprising electricalcircuitry configured to perform an algorithm to generate and display onan electronic display a rate of change graph that provides a visualindication as to how fast said differential pressure measurements arechanging, and whether a direction of change is increasing or decreasing,or neither.
 7. The device of claim 1, further comprising a capture valuebutton and electrical circuitry configured to capture a differentialpressure measurement as a captured value when said capture value buttonis depressed without interrupting an electronic display of real timedifferential pressure measurements.
 8. The device of claim 7, furthercomprising electrical circuitry configured to display said capturedvalue and continue said uninterrupted display of said real timedifferential pressure measurements.
 9. The device of claim 7, furthercomprising electrical circuitry configured to store in memory anddisplay more than one captured value and continue said uninterrupteddisplay of said real time differential pressure measurements.
 10. Thedevice of claim 7, further comprising at least one pressure sensor influid communication with one or both of said first and said second fluidlines and configured to measure fluid pressure in one or both of saidfirst and said second fluid lines.
 11. The device of claim 1, furthercomprising electrical circuitry configured to permit wirelesstransmission and reception of data.
 12. The device of claim 11, furthercomprising electrical circuitry configured to permit wireless connectionto a mobile device whereby calibration of said backflow testing deviceis controllable remotely using said mobile device.
 13. The device ofclaim 1, further comprising electrical circuitry configured to permitsaving in memory and wirelessly transmitting a captured value and acaptured value identifier corresponding to said captured value.
 14. Thedevice of claim 1, further comprising hydraulic circuitry to provide a2-valve backflow testing device.
 15. The device of claim 1, furthercomprising hydraulic circuitry to provide a 3-valve backflow testingdevice.
 16. The device of claim 1, further comprising hydrauliccircuitry to provide a 5-valve backflow testing device.
 17. The deviceof claim 1, further comprising hydraulic circuitry configurable toprovide any one of a 2-valve backflow testing device, a 3-valve backflowtesting device, or a 5-valve backflow testing device.
 18. A digitalbackflow testing device comprising: a first fluid line connectable to afirst source of fluid and a first fluid pressure therefor; a secondfluid line connectable to a second source of fluid and a second fluidpressure therefor; electrical circuitry configured to providedifferential pressure measurements of a pressure differential betweensaid first and said second fluid lines; and a capture value button andelectrical circuitry configured to capture a differential pressuremeasurement as a captured value when said capture value button isdepressed without interrupting an electronic display of real timedifferential pressure measurements.
 19. A digital backflow testingdevice comprising: a first fluid line connectable to a first source offluid and a first fluid pressure therefor; a second fluid lineconnectable to a second source of fluid and a second fluid pressuretherefor; electrical circuitry configured to provide differentialpressure measurements of a pressure differential between said first andsaid second fluid lines; and electrical circuitry configured to performan algorithm to generate and display on an electronic display a rate ofchange graph that provides a visual indication as to how fast saiddifferential pressure measurements are changing, and whether a directionof change is increasing or decreasing, or neither.
 20. A digitalbackflow testing device comprising: a first fluid line connectable to afirst source of fluid and a first fluid pressure therefor; a secondfluid line connectable to a second source of fluid and a second fluidpressure therefor; electrical circuitry configured to providedifferential pressure measurements of a pressure differential betweensaid first and said second fluid lines; and hydraulic circuitry toprovide a 5-valve backflow testing device.